The h Bar

Does anyone know of a good video editing program that is online, easy to use, can take video and make it slow motion, add overlays of various types, do voiceovers, splice together video, and take gif files?

(Lots of requirements, I know)

Zacharee1

you'd probably have better luck at Software Recommendations

0celo7

1:20 AM

@NeuroFuzzy tell me something interesting Dr. Algebraic Geometry

Zacharee1

@SirCumference Not Passover?

heather

@Zacharee1, thanks for the site recommendation

Sir Cumference

1:37 AM

@Zacharee1 Oh yeah, that too

0celo7

@SirCumference You forgot the Passah!!??

Not a real Jew :(

Sir Cumference

Passah?

0celo7

Pessach

Pessach, auch Passah oder Pascha genannt (hebräisch פֶּסַח‎ pésach?/i; aramäisch פַּסְחָא pas-cha; griechisch (Septuaginta und NT) πάσχα pás-cha; wörtlich „Vorüberschreiten“), gehört zu den wichtigsten Festen des Judentums. Es erinnert an den Auszug aus Ägypten, also die Befreiung der Israeliten aus ägyptischer Sklaverei. Die Nacherzählung (Haggada) dieses im Buch Exodus des Tanach erzählten Geschehens verbindet jede neue Generation der Juden mit ihrer zentralen Befreiungserfahrung. Das Pessach wird in der Woche vom 15. bis 22., in Israel bis zum 21. Nisan gefeiert. Es ist ein Familienfest mit…

I'm German

Sir Cumference

You meant Pessach

0celo7

no

Sir Cumference

1:48 AM

@0celo7 Bull

0celo7

> Pessach, auch Passah

@SirCumference Ask @ACuriousMind

Sir Cumference

You've told us you're american multiple times

0celo7

Well I'm American

Sir Cumference

what

Oh, you're of German heritage

0celo7

No, I was born and raised in Germany

I speak German fluently

NeuroFuzzy

3:10 AM

@0celo7 ehm polynomials are cool?

Subspaces of Noetherian toplological spaces are Noetherian in their induced topology?

0celo7

@NeuroFuzzy define pls

@NeuroFuzzy ok that I doubt

NeuroFuzzy

@0celo7 They are though! So yeah, AG Hartshorne chapter 1 does mostly classical algebraic geometry, apparently? Before all of the abstraction.

and one of the things you do is define your topology on, say, $\mathbb{R}^2$ by saying that a set is closed iff it is the zero set of some polynomial in two variables

0celo7

hmm

why

user116211

Hey @0celo7, you know the proof of subset of countably infinite set being countable?

0celo7

It's pretty obvious, no?

user116211

3:17 AM

@0celo7 It's not trivial though.

0celo7

I don't particularly care for such proofs, but what do you need?

user116211

Anyways, I'm having a bit problem in comprehending a statement; wait....

user116211

user116211

$A$ is a subset of a countably infinite set $B;$ they took a function $g$ such that

> $g(1)$ is the first natural number $j$ for which $f(j)$ belongs to $A\,.$

Then after two lines or so, they wrote
> It is clear that $f\circ g$ is a one-to-one mapping with domain $\mathbb N$ and image contained in $A\,.$ An __induction argument shows that $g(j)\geq j$ for all $j\,.$__ ...

NeuroFuzzy

@0celo7 Well it's nice to know about polynomials innit? Ehm more seriously I don't know. Polynomials are commutative rings over fields (w/ appropriate definitions anyways) so that's a nice place to generalize. It really becomes general in the next chapter though, where we're talking about sheaves.

I'm just along for the ride. Weird 3D shapes are neat anyways and that's what polynomials "are".

user116211

3:19 AM

WTH is that; why doesn't the quoting work?

user116211

Anyways,

0celo7

Multiline breaks markdown.

user116211

What is the significance of the statement that $g(j)\geq j~~\forall j$ in the proof?

user116211

I'm not getting that.

0celo7

It's the justification for the line "Hence $x$ belongs..."

user116211

3:25 AM

They have already showed the one-to-one correspondence between $\mathbb N$ and $A\,.$ So, the statement hence, $x$... is implied, isn't it?

0celo7

No

You need that set there to terminate

you know it terminates at $f(g(k))$ because of the $j$ thing

@MAFIA36790 btw, I had the last word and won ;)

user228700

Hi everyone :-)

user116211

Hello.

user116211

@0celo7 Okay, I'm re-reading it to get the point.

0celo7

WORD STOP BREAKING

Ramanujan

3:33 AM

@0celo7 ican f in infinity in Fermat's theorem

0celo7

I was obviously not being serious

your question does not have an answer without you defining infinity

and even then

it's just going to be infinity

user228700

@MAFIA36790: Are u fairly comfortable with this topic now:?

user228700

1

Q: If the velocity of an object, rotating on a vertical circle, at the topmost point is zero, how can it loop the whole circle?

Normally, if a body is attached to a string & is rotated in a vertical circle, then to loop the whole circle, the rope must not slack at the topmost point & there should be a velocity for having centripetal force. For this, the minimum initial velocity required is $\sqrt{5gr}$, $r$ being the rad...

user116211

Sure I'm; but I'm currently busy in a theorem; but you can ask - if I need to respond, I will later.

0celo7

^pretty amazing Word skills

user228700

3:38 AM

Okay, well, my only question is this-does the rod keep on rotating after reaching the top simply because it is in an unstable equilibrium at the top?

0celo7

@Kaumudi Doubt?

user116211

BTW, checking at the post, I should have never asked that at the first place; I figured it out by myself later and even answered related queries.

user228700

@0celo7 Gah! :-P OK now?

0celo7

:)

user116211

@Kaumudi Because there is still non-zero velocity of the particle at the top and there is inward force; so it is inevitable it would rotate.,

user228700

3:40 AM

@MAFIA36790 There is non-zero velocity at the top?

user116211

@Kaumudi Wait; I need to re-count the topic; let me read...

user116211

the post.

user228700

@MAFIA36790 Sure...

user116211

Well, now after reading, I assert there must be a non-zero velocity at the top no matter how infinitesimal might be.

user116211

It shouldn't be zero but can be arbitrarily close to zero.

user228700

3:44 AM

Really?

user116211

Yes.

user116211

The book directly wrote the velocity is zero but that is wrong.

user116211

The initial velocity must be $\gt 2\sqrt{gr}\,.$

user228700

Yes, I was going to upload a picture of the book...

0celo7

my fingers smell weird

user228700

3:46 AM

But I'm sure that $v=0$ is the condition to be applied while solving problems, yeah..?

0celo7

reminds me of these ink erasers we used in grade school in Germany

@ACuriousMind knows the smell

user116211

@0celo7 Ask John Rennie; he is an expert in all smell.

user116211

@0celo7 okay.

0celo7

He is dead :((((((((((((

user116211

WTH ;/

user228700

3:47 AM

@0celo7 What the hell is wrong with you?!

0celo7

many things

@Kaumudi should I start listing?

user228700

@0celo7 No, thanks :-P

user116211

@Kaumudi yes, it is the limiting condition that is used to find the limiting value of the initial velocity.

user228700

@MAFIA36790 I don't think this is correct :/

0celo7

@MAFIA36790 if you want to read the geometry book by Kreyszig I will read with you

user116211

3:48 AM

@0celo7 I have that book and would love to but I'm currently with Royden. Nevertheless, start reading it; it would be exciting.

0celo7

I read it in high school

but I didn't appreciate it

Now it would be a lot easier to read + I'd understand all of it

It's not an advanced book at all

user116211

@0celo7 It's Kreyszig, dude.

0celo7

What?

user116211

This guy wrote introductory texts only.

user228700

@MAFIA36790:

user228700

3:50 AM

0celo7

@MAFIA36790 ok, sure

We can read something advanced if you want?

user116211

@0celo7 For me, Kreyszig would be advanced too as I have not studied geometry still; but anything you wish; that would be exciting.

user116211

@Kaumudi I've seen; but tell me if the velocity is zero at the top, why would it rotate?

0celo7

I think the book requires only calculus

user116211

@0celo7 Is it? Great!!

0celo7

3:52 AM

But I think it would be nice to learn some concrete geometry

Before I embark on the journey of classifying (i) homogeneous spaces (ii) symmetric spaces (iii) constant curvature spaces

which will take a while

user116211

Go on!!

user228700

@MAFIA36790 No, I meant to highlight the fact that the velocity at the lowest point is $\sqrt{4gl}$ and not $\sqrt{2gl}$, $l$ being the length of the string.

0celo7

@MAFIA36790 ok I'll start tomorrow if I have time

I will fly through the book

user116211

@Kaumudi where did I write that?

user116211

@0celo7 Sure.

user116211

3:54 AM

Meanwhile I have to read Royden and then Kelley.

user116211

Then there is linear algebra of Hofmann.

0celo7

oh I don't want to do PhD math

no linear algebra

user116211

Lanczos is always there; so I'm really full in my hands.

user228700

@MAFIA36790 Oh, crap, I read MathJax wrongly, sorry. (It doesn't render on my phone, as u know)

0celo7

@MAFIA36790 Can you take a topology course?

user116211

3:57 AM

@0celo7 The book is really great; it has some good problems but very few.

0celo7

It's much better than reading a book

@MAFIA36790 oh, anything?

hmm, we should read Advanced General Relativity by Stewart

I should really read that one day

This summer should be the summer of GR

@MAFIA36790 We could also read Weinberg's GR.

that requires calculus

some PhD linear algebra

and special relativity

Is your internet lagging?

user116211

@0celo7 yes.

0celo7

Is India drifting out to sea?

user116211

@0celo7 YES!

user116211

Anyways, I'm reading Kelley to get into topology myself before my university starts.

0celo7

4:05 AM

what's up with Pakistan these days

user116211

@0celo7 No idea.

0celo7

no war?

user116211

:(

user116211

France has decided to investigate the war-crimes of Soviet Russia and Putin.

user116211

That's an interesting news.

user116211

4:06 AM

Putin is a peace-loving man.

0celo7

Agreed.

user116211

@0celo7 The determinants chapter of Hofmann contains Grassman ring.

0celo7

When I think "peace" I think "Putin, Bush, Kennedy, Hitler"

user116211

I'm waiting to read the content.

0celo7

In that order

sometimes Truman too

at the end

user116211

4:08 AM

increasing or decreasing...

0celo7

@MAFIA36790 Ah yes

That can get nasty when the field has characteristic 2.

user116211

ohh.

0celo7

One has to deal with so-called "cross section permutations"

user116211

We are working with the fields of zero characteristic.

0celo7

Ok that makes things nice

trivial even

that's not PhD algebra then

more like

user116211

4:10 AM

@0celo7 See? No PhD level.

0celo7

high school algebra

user116211

Yes.

0celo7

PhD high school though

user116211

That's why I told to read that book.

user116211

@0celo7 NO.

0celo7

4:11 AM

I understand linear algebra just fine

ok gotta write this lab report

bye

user116211

good.

user116211

@0celo7 o/

user116211

Another linear algebra problem on orthogonalization process:

user116211

16

Q: The need for the Gram–Schmidt process

As far as I understood Gram–Schmidt orthogonalization starts with a set of linearly independent vectors and produces a set of mutually orthonormal vectors that spans the same space that starting vectors did. I have no problem understanding the algorithm, but here is a thing I fail to get. Why do...

linear-algebra orthonormal gram-schmidt

0celo7

GS is trivial

LA is PhD level because solving equations is PhD level

user116211

4:16 AM

Anyways, back to that theorem; it has been late talking...

0celo7

@Kaumudi where is John?

user116211

He is enjoying his beer-chair.

0celo7

he's not drinking beet at 6AM

I hope not at least

he'd be a terrorist alcoholic if so

user116211

Anyways, I have to show $g(j)\geq j$ by inductive process...

0celo7

as my probability prof would say

user116211

4:21 AM

I know $g(1)\geq 1$ by the given condititon and the definition of $\mathbb N\,.$

0celo7

"trivial"

@MAFIA36790 Yes!

user116211

And given $g(r)\geq r,$ I have to show $g(r+1)\geq r+1\,.$

user116211

That means, I have to show $g(r+1)\geq g(r) + g(1)\,.$

user116211

I know the equality arises when $g$ is linear.

0celo7

proof?

user116211

4:22 AM

But how to show the inequality case?

0celo7

$g$ is certainly not linear...

user116211

@0celo7 yes.

user116211

But the equality arises when $g$ is linear, isn't it?

0celo7

do you know that $g(r+1)>g(r)$?

user116211

@0celo7 WoW! I mean how?

0celo7

4:24 AM

Figure that out

But once you have that

$g(r+1)>g(r)\ge r$

So $g(r+1)\ge r+1$

user116211

okay.

user228700

@0celo7 I imagine that he's sleeping :-) He'll be here in another hour at most, I think...that's what he told yesterday.

0celo7

hmm

sleeping

6 FEET UNDER

user116211

O.o

0celo7

omg what is wrong with me

user228700

4:30 AM

@0celo7 Sigh.

user116211

He is a secret member of SETI. Probably contacting aliens with his servers.

user228700

@0celo7 Exactly.

0celo7

@Kaumudi fix me

user228700

@0celo7 Sorry man, I'm too busy fixing myself.

0celo7

@ACuriousMind has abandoned me

like wth

when are the mods being elected anyway

user116211

4:31 AM

ACM has become really busy lately.

0celo7

that's no excuse

user116211

He is also busy in preparing his victory speech after the election.

0celo7

I'd be surprised if he won

user116211

O.o

user116211

Yeh, i know there is the tpg guy.

0celo7

4:33 AM

and Jim

Jim has a PhD in likability

honestly if you don't like Jim, leave

user116211

There are two posts.

0celo7

yes

I did not vote for ACM

user116211

Jim is good; I want him.

0celo7

tpg is good, too

we need an engineer on the team

user116211

@0celo7 WTH; but I respect your choice.

0celo7

4:34 AM

there are better candidates

ACM would be more prone to mod abuse, too

user116211

ACM know what moderatorship actually is.

user116211

@0celo7 Oh Lord ;/

0celo7

ACM has volatile warrior's blood

user116211

Take some rest....

0celo7

no

I'm doing this lab report

user116211

4:36 AM

Then complete it.

user116211

I meanwhile figure out that inequality.

0celo7

it's not hard

use trichotomy

rule out the two other cases

John Rennie

4:54 AM

@Kaumudi or indeed in another 25 minutes!

0celo7

dude I keep thinking you're dead

John Rennie

Not for a few decades yet - hopefully :-)

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